powerpc/pseries/pci: Introduce rtas_prepare_msi_irqs()

This splits the routine setting the MSIs in two parts: allocation of
MSIs for the PCI device at the FW level (RTAS) and the actual mapping
and activation of the IRQs.

rtas_prepare_msi_irqs() will serve as a handler for the PCI MSI domain.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-3-clg@kaod.org

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index d2d090e..4bf14f2 100644 (file)
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -373,12 +373,11 @@ static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
        pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
 }
 
-static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
+static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int nvec_in, int type,
+                                msi_alloc_info_t *arg)
 {
        struct pci_dn *pdn;
-       int hwirq, virq, i, quota, rc;
-       struct msi_desc *entry;
-       struct msi_msg msg;
+       int quota, rc;
        int nvec = nvec_in;
        int use_32bit_msi_hack = 0;
 
@@ -456,6 +455,22 @@ again:
                return rc;
        }
 
+       return 0;
+}
+
+static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
+{
+       struct pci_dn *pdn;
+       int hwirq, virq, i;
+       int rc;
+       struct msi_desc *entry;
+       struct msi_msg msg;
+
+       rc = rtas_prepare_msi_irqs(pdev, nvec_in, type, NULL);
+       if (rc)
+               return rc;
+
+       pdn = pci_get_pdn(pdev);
        i = 0;
        for_each_pci_msi_entry(entry, pdev) {
                hwirq = rtas_query_irq_number(pdn, i++);